1. Field of the Invention
The invention relates to a method and arrangement for improving the digital-signal-generated grayscale resolution of a monochrome visual display unit to which the digital signals from an image source can be supplied over an n-bit wide RGB wire pair.
2. Description of the Related Art
In the medical field, monochrome visual display units, which must meet very high requirements in terms of grayscale resolution, are used particularly to interpret X-ray images. For this type of use, monochrome visual display units are superior to color units. The current requirements in terms of grayscale resolution call for 10-bit wide grayscale signals, enabling 1024 grayscale gradations on a monochrome visual display unit.
If such a monochrome visual display unit is connected to a 24-bit color-image source by a DVI cable (Digital Video Interface cable), which has one wire pair for each 8-bit wide RGB channel, it is not possible to visually represent all the RGB color information transmitted to the monochrome visual display unit in a “correct” grayscale on that visual display unit. This means that information is lost, which can have a disturbing effect on a viewer. For example, RGB signals with color information (0, 255, 0), (255, 255, 0) or (0, 255, 255), which a color visual display unit displays as the colors green, yellow and turquoise, appear white on a monochrome visual display unit.